diff options
Diffstat (limited to 'fs/smb/client/fscache.c')
| -rw-r--r-- | fs/smb/client/fscache.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/fs/smb/client/fscache.c b/fs/smb/client/fscache.c new file mode 100644 index 000000000000..01424a5cdb99 --- /dev/null +++ b/fs/smb/client/fscache.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * CIFS filesystem cache interface + * + * Copyright (c) 2010 Novell, Inc. + * Author(s): Suresh Jayaraman <sjayaraman@suse.de> + * + */ +#include "fscache.h" +#include "cifsglob.h" +#include "cifs_debug.h" +#include "cifs_fs_sb.h" +#include "cifsproto.h" + +/* + * Key for fscache inode. [!] Contents must match comparisons in cifs_find_inode(). + */ +struct cifs_fscache_inode_key { + + __le64 uniqueid; /* server inode number */ + __le64 createtime; /* creation time on server */ + u8 type; /* S_IFMT file type */ +} __packed; + +static void cifs_fscache_fill_volume_coherency( + struct cifs_tcon *tcon, + struct cifs_fscache_volume_coherency_data *cd) +{ + memset(cd, 0, sizeof(*cd)); + cd->resource_id = cpu_to_le64(tcon->resource_id); + cd->vol_create_time = tcon->vol_create_time; + cd->vol_serial_number = cpu_to_le32(tcon->vol_serial_number); +} + +int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) +{ + struct cifs_fscache_volume_coherency_data cd; + struct TCP_Server_Info *server = tcon->ses->server; + struct fscache_volume *vcookie; + const struct sockaddr *sa = (struct sockaddr *)&server->dstaddr; + size_t slen, i; + char *sharename; + char *key; + int ret = -ENOMEM; + + if (tcon->fscache_acquired) + return 0; + + mutex_lock(&tcon->fscache_lock); + if (tcon->fscache_acquired) { + mutex_unlock(&tcon->fscache_lock); + return 0; + } + tcon->fscache_acquired = true; + + tcon->fscache = NULL; + switch (sa->sa_family) { + case AF_INET: + case AF_INET6: + break; + default: + mutex_unlock(&tcon->fscache_lock); + cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family); + return -EINVAL; + } + + memset(&key, 0, sizeof(key)); + + sharename = extract_sharename(tcon->tree_name); + if (IS_ERR(sharename)) { + mutex_unlock(&tcon->fscache_lock); + cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__); + return PTR_ERR(sharename); + } + + slen = strlen(sharename); + for (i = 0; i < slen; i++) + if (sharename[i] == '/') + sharename[i] = ';'; + + key = kasprintf(GFP_KERNEL, "cifs,%pISpc,%s", sa, sharename); + if (!key) + goto out; + + cifs_fscache_fill_volume_coherency(tcon, &cd); + vcookie = fscache_acquire_volume(key, + NULL, /* preferred_cache */ + &cd, sizeof(cd)); + cifs_dbg(FYI, "%s: (%s/0x%p)\n", __func__, key, vcookie); + if (IS_ERR(vcookie)) { + if (vcookie != ERR_PTR(-EBUSY)) { + ret = PTR_ERR(vcookie); + goto out_2; + } + pr_err("Cache volume key already in use (%s)\n", key); + vcookie = NULL; + trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, + netfs_trace_tcon_ref_see_fscache_collision); + } else { + trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, + netfs_trace_tcon_ref_see_fscache_okay); + } + + tcon->fscache = vcookie; + ret = 0; +out_2: + kfree(key); +out: + kfree(sharename); + mutex_unlock(&tcon->fscache_lock); + return ret; +} + +void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) +{ + struct cifs_fscache_volume_coherency_data cd; + + cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache); + + cifs_fscache_fill_volume_coherency(tcon, &cd); + fscache_relinquish_volume(tcon->fscache, &cd, false); + tcon->fscache = NULL; + trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, + netfs_trace_tcon_ref_see_fscache_relinq); +} + +void cifs_fscache_get_inode_cookie(struct inode *inode) +{ + struct cifs_fscache_inode_coherency_data cd; + struct cifs_fscache_inode_key key; + struct cifsInodeInfo *cifsi = CIFS_I(inode); + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); + + key.uniqueid = cpu_to_le64(cifsi->uniqueid); + key.createtime = cpu_to_le64(cifsi->createtime); + key.type = (inode->i_mode & S_IFMT) >> 12; + cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd); + + cifsi->netfs.cache = + fscache_acquire_cookie(tcon->fscache, 0, + &key, sizeof(key), + &cd, sizeof(cd), + i_size_read(&cifsi->netfs.inode)); + if (cifsi->netfs.cache) + mapping_set_release_always(inode->i_mapping); +} + +void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) +{ + if (update) { + struct cifs_fscache_inode_coherency_data cd; + loff_t i_size = i_size_read(inode); + + cifs_fscache_fill_coherency(inode, &cd); + fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size); + } else { + fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL); + } +} + +void cifs_fscache_release_inode_cookie(struct inode *inode) +{ + struct cifsInodeInfo *cifsi = CIFS_I(inode); + struct fscache_cookie *cookie = cifs_inode_cookie(inode); + + if (cookie) { + cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie); + fscache_relinquish_cookie(cookie, false); + cifsi->netfs.cache = NULL; + } +} |